Ansible - Radically simple configuration-management, application deployment, task-execution, and multi-node orchestration engine
Nifty - Manage projects, work, and communications in one place.
Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
ZenHub - ZenHub is how the world's best software teams work together. Trusted by NASA, Docker, and Rackspace. Start free today!
Puppet Enterprise - Get started with Puppet Enterprise, or upgrade or expand.
Intercom on Product Management - The ultimate resource for aspiring product managers